查询词典 algebraic closure operator

Stands for the Laplace operator in R~N, u and v represent the densities of two species, a, b, c, d,γare positive constants,α,β, m, n each is more than the positive number 1,γmeasures the saturation level of the species.

充分光滑，△为R~N中Laplace算子，u，v分别表示区域Ω中两种群的密度，参数a、b、c、d、γ均大于0，α、β、m、n均是大于1的正数，γ是测量种群饱和项的水平。

Named for Pierre-Simon Laplace, the equation states that the sum of the second partial derivatives (the Laplace operator, or Laplacian) of an unknown function is zero.

以法国数理学家拉普拉斯命名的这个方程式表述如下：一个未知函数的二级偏微商之和等于零。

Firstly, edge extracting is conducted with a laplace operator for a k frame image of fk and a k-1 frame image of fk-1 collected by a camera; secondly, difference calculus is conducted for images of two frames whose edge is extracted, and a difference image of D is obtained; thirdly, average filtering and binary processing is conducted for the difference image of D, fourthly, the image which is processed of binary is judged, i.e. when the difference of a pixel in the difference image is more than the set threshold value, the pixel is confirmed as a target pixel; otherwise, the pixel is a static background pixel.

首先对摄像头采集的第k帧图像f k和第k-1帧图像f k-1分别采用laplace算子进行边缘提取，然后对经过边缘提取的两帧图像进行差分运算，得到差分图像D，然后对差分图像D进行均值滤波和二值化处理，最后对二值化后的图象进行判断，即认为当差分图像中某一个像素的差大于设定的阈值时，则认为该像素是目标像素，反之则认为是静止不动的背景像素。

A Prove that d/dx is a linear operator on V. b You can put a coordinate system on V by mapping p to p(0, p(1), p(2).(Please imagine that flipped 90 degrees so it is a column.) Find the matrix that represents d/dx in this coordinate system.

1证明d/dx是V上的线性算子；2你可以将p映射到p(0， p(1)， p(2)，从而给V加上坐标系（想象将其翻转90°，形成柱体），找出在此坐标系中代表d/dx的矩阵。

In the days of sailing vessels the crew were afraid they would be becalmed on the ocean.

在使用帆船的时代，船员们担心他们会因为无风而无法在海洋上航行。

As long as foreign donors pay the PA's salary bill, few expect a new intifada.

只要外国继续为巴权力机构的薪水买单，希望发动新暴动的人便寥寥无几。